Mitsubishi MELSEC Q Series Programming Manual page 341

When the High Performance model QCPU/Process CPU/Redundant CPU/Universal model
QCPU or LCPU is used
DI
IMASK
EI
Setting
Data
S
Function
DI
(1) Disables the execution of an interrupt program until the EI instruction has been executed,
even if a start cause for the interrupt program occurs.
(2) A DI state is entered when power is turned ON or when the CPU module is reset.
EI
The EI instruction is used to clear the interrupt disable state resulting from the execution of
the DI instruction, and to create a state in which the interrupt program designated by the
interrupt pointer number enabled by the IMASK instruction and the fixed cycle execution
type program can be executed.
When the IMASK instruction is not executed, I32 to I47 are disabled.
In
: Head number of the devices where the interrupt mask data is stored (BIN 16 bits)
S
Internal Devices
R, ZR
Bit Word
––
Sequence program
DI
Sequence program
EI
FEDN
Interrupt programs
Sequence program
J \
U \G
Bit Word
––
Even if a cause of interrupt occurs during
the execution of the sequence program
between the DI and EI instructions,
execution of the interrupt program is
suspended until the processing of the
sequence program is completed.
DI,EI,IMASK
DI
IMASK S
EI
Zn Constants Other
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